Data will be collected from around Minnesota and a summary map, which indicates where significant captures have occurred, will be prepared. This map and a short newsletter will be posted to the SWROC website each week. The newsletter will contain information on the black cutworm, its biology, damage to crops and management decisions.

Insecticide Resistance Management in Soybean

﻿Insecticide ﻿(and miticide) resistance is a heritable decrease in a pest population's susceptibility to a pesticide, meaning the genetics are passed from generation to generation. As pest populations become less susceptible to a pesticide, the utility of that pesticide becomes less and less effective to a point where the pesticides may become effectively lost as tools for management of that pest. Read the entire Extension Fact Sheet "Insecticide Resistance Management in Soybeans" (pdf) to learn IPM strategies recommended for insect and mite pests in MN soybeans. This face sheet was written by Robert Koch and Ian MacRae, Extension Entomologists, as well as Bruce Potter, IPM Specialist.

On May 16, 2013 two studies were planted in a Brown County, MN corn field. The field had been in continuous corn for seven years. Significant corn rootworm (CRW) damage to multiple Bacillus thuringiensis protein expressing rootworm resistant corn (Bt-RW) events was observed in this field during 2012. The research was conducted by Bruce Potter, SWROC IPM Specialist with assistance from Travis Vollmer and Jeff Irlbeck, both SWROC Research Plot Technicians.

2013 Weed Trial Results

Armyworm Information

Written by Bruce Potter. The mere mention of armyworms can cause angst in those who have experienced the severe outbreaks of the early 80s and earlier and the news of armyworms in the area causes can trigger unnecessary insecticide applications. Fortunately, other than taking some time, scouting for armyworms is fairly straight forward and they are easily controlled with insecticides. Read more about where armyworms are being found. MN has not had a widespread armyworm outbreak since the 90's. I don't believe this year will approach that. Devastating if you have a field with the problem though.

Make sure there are still larvae present before you treat. If this is a typical armyworm infestation year, many fields will be treated after the larvae have finished feeding...or before they begin. Based on sizes of larvae reported, this will be over in a week or less. Read True Armyworm: The 2013 Infestation (pdf).

Are you interested in watching crop growth and development throughout the season? Bruce Potter, IPM Specialist, ReNae Clark, Potter's summer intern, and Steve Quiring, Scientist, monitored the growth and development of corn and soybeans throughout the 2013 growing season. Pictures include the date of planting, the current date, growing degree days calculated from the planting date, and crop stage. Images were taken on the dates below.

High Yield Studies - A Stepwise Approach

A 2004 - 2010 study at the U of M SWROC examined the effect of crop rotation and management on corn and soybean yields. Intensively managed continuous corn out-yielded conventionally managed rotated and continuous corn but yielded less than invensively managed rotated corn. Both corn and soybean yields were increased by rotation but more than two years of corn were needed to produce a soybean yield response over an annual rotation. This project was conducted by Bruce Potter and funded by the MN Soybean Research and Promotion Council and the MN Corn Research and Promotion Council. Read the entire report (pdf).

Since 2009, an increasing number of fields planted to Bt‐RW traited corn have shown unexpected root injury from corn rootworms. Problems were first reported in the SE and SW corners of Minnesota but since then have been reported from an ever wider geography in Minnesota. While the majority of Minnesota reports regarding performance problems have come from VT3 hybrids, all traits have experienced at least occasional problems. Previous data indicates no yield benefit for at‐plant insecticides on Bt‐RW hybrids when the trait is performing well (and no early season stand reducing insect problems occur). A yield response to at‐plant soil insecticide on Bt‐RW traited corn could indicate rootworm damage, and perhaps provide a sign of developing trait resistance.

You have the ability to determine yield impacts from corn rootworms in your fields if applying a soil insecticide application at planting. Investing a minor amount of time at planting by creating treated and untreated strips could provide an indicator of developing resistance problems and field‐specific information on the value of soil insecticides. In the process, you could also help us determine the extent of this problem in Minnesota…if you’re willing to be a cooperator by sharing your data. Read the entire article (pdf).

Youtube Video on SCN

Check out the Youtube Video on Soybean Cyst Nematode created on July 6, 2012. This is just a trial run to test camera techniques and sppeed of turn around. It is crude but I hope it provides some information on scouting SCN. Martin Scorcese we ain't. More seriously, if you think this format is a good way to present techniques on scouting and would like more, let us know and we'll keep practicing.